Joo Won has always been very supportive of his "Yong Pal" co-star Kim Tae Hee.

At the press conference for the medical melodrama he spoke about how excited he had been to work with her and how he was not disappointed when he did.

"I think I fell for noona more at the first script reading. I thought, 'how could someone with her looks also have such a good personality?' There's beauty in personality as well. The more I see her, the prettier I think she is and I think I will have fun working with her."

On The SBS program "Healing Camp," healso spoke about his first impressions, "On our first script reading day, I came to think that she was not called Pretty Tae Hee for no reason."

When Kim received criticism for her acting in the earlier episodes, he defended her, saying that her acting was heartfelt.

"Kim Tae Hee is trying hard to show a different side of herself than she did in the past," he said. "You can say that she is completely absorbed in her new character Han Yeo Jin. She's trying to let herself go and act as naturally as possible."

He comforted her when she was criticized and the couple became good friends. Despite the criticism, Kim Tae Hee went on to win the Top Excellence Award for Best Actress at the 2015 Korea Drama Awards.

Joo Won has a history of being kind to and complimentary towards his female co-stars, praising Choi Kang Hee, Moon Chae Won and Jin Se Yeon, but if he had to pick the best it would be Kim Tae Hee. When the "Healing Camp" host asked him which actress was his favorite, she won.

"I wondered how she could be so pure like that when she had been in the entertainment business for such a long time," he said. "Also, she was a good actress who created the feelings that allowed me to love Yeo Jin."

The feeling was apparently mutual. Kim said she got very close to him during the filming.

"I got closer to him to the point I could say that I can't get any closer. Among all the actors I've worked with, I got the closest to him and was able to communicate with him the best."

In fact, Kim would like to have a son just like Joo Won.

"He's very masculine when he's acting but he often uses sweet babying words. It was to the point where I thought it'd be nice to have a son like him. The women around him melt when confronted with Joo Won's charms."